Semin scored from well outside the blue line on the first shot of overtime Saturday to give the Capitals a 4-3 victory over Boston and help them gain a point on the Bruins in the race for home ice in the East. Washington, which trails Boston by eight points, has won three of the teams' four meetings this year.

"I don't think it gives us any advantage, but it does give us the thought that over four games so far we've been able to compete with maybe the best team in the league," Capitals coach Bruce Boudreau said. "If it gets down to it in the (conference) finals ... then it would probably be a good series."

Zdeno Chara scored his 100th career goal with 4:37 left in regulation to force overtime, but it didn't last long. Soon after the first faceoff, Semin brought the puck over the red line and launched a hard but seemingly harmless slapper at the net that hit off Tim Thomas' glove and trickled through for the winner.

"It's very frustrating. I feel bad for the team that that's the way it had to end," Thomas said. "He who laughs last laughs hardest. We'll see what happens."

Alex Ovechkin scored his league-leading 45th goal of the season for the Capitals, and Jose Theodore made 34 saves. But Theodore let Chara's shot sneak inside the post on his glove side to allow Boston to force overtime and keep the Capitals from gaining two points in the standings.

"We still have 19 games so anything can happen," Ovechkin said. "Every game against them we got at least one point, so it's good for our mentality that we can beat them and it doesn't matter if first or second. I think it's all about us. If we play our game and our system we can beat everybody."

Bruins coach Claude Julien criticized his team's effort but couldn't blame Thomas, who leads the league in goals-against and save percentage.

"He's given us too much to be worried about that," Julien said. "Call it a lucky goal or a bad goal; we can call it what we want. But those are shots that shouldn't go in."

Julien was even more critical of the Capitals, accusing them of getting overconfident because of their head-to-head record.

"I have heard them say they're in our heads," he said. "They do a lot of talking. I don't think they do a lot of research."

Thomas stopped 28 shots for Boston. Marc Savard had three assists, Phil Kessel had a goal and an assist and Matt Hunwick also scored for the Bruins, who lost at home for just the fourth time in their last 27 games. Savard, who left Thursday night's game with an unspecified injury, had two assists for the third time in four games.

Ovechkin scored his 14th goal in 15 games when he squeezed a wrist shot inside the post to beat Thomas and give the Capitals a 2-1 lead 8:48 into the second period. But Kessel scored just 18 seconds later, on a cross-ice pass from Savard to tie it.

Tomas Fleischmann broke the tie with 17:40 left when he banked a shot in off defenseman Dennis Wideman.

Nicklas Backstrom also scored for Washington.

Notes: Capitals forward Michael Nylander was a healthy scratch. ... Boston forward Milan Lucic, who also sat out the third period of Thursday's game with an injury, was scratched. ... Backstrom extended his point-scoring streak to eight games.